doctype
html(lang="en")
    head
        meta(name="viewport", content="width=device-width, initial-scale=1.0")
        meta(http-equiv="Content-Type", content="text/html; charset=UTF-8")
        title Border
        link(rel="stylesheet", type="text/css", href="../test.css")
    body
        .tt
            .test ttttt
            .border-box inner
        .tt2
            .box
                .box-flex inner
                .box-flex inner
                .box-flex2 inner
        .layout-demo
            #header.inner-padding.border.box-sizing Hearder content
            #content.clearfix
                #left.aside.inner-padding.border.box-sizing Left side
                #main-content.article.inner-padding.border.box-sizing Main content
            #footer.inner-padding.border.box-sizing footer content